The two most important phenomena impacting telecommunications over the past decade have been explosive parallel growth of both the internet and mobile telephone services. The internet brought the benefits of data communications to the masses with email, the web, and ecommerce; while mobile service has enabled "follow-me anywhere/always on" telephony. The internet helped accelerate the trend from voice-centric to data-centric networking. Data already exceeds voice traffic and the data share continues to grow. Now these two worlds are converging. This convergence offers the benefits of new interactive multimedia services coupled to the flexibility and mobility of wireless. To realize the full potential of this convergence, however, we need broadband access connections.

Here we compare and contrast two technologies that are likely to play important roles: Third Generation mobile ("3G") and Wireless Local Area Networks ("WLAN") . The former represents a natural evolution and extension of the business models of existing mobile providers. In contrast, the WiFi approach would leverage the large installed base of WLAN infrastructure already in place. We use 3G and WiFi as shorthand for the broad classes of related technologies that have two quiet distinct industry origins and histories.

Speaking broadly, 3G offers a vertically -integrated , top -down , service - provider approach to delivering wireless internet access , while WiFi offers an end -user -centric , decentralized approach to service provisioning. We use these two technologies to focus our speculations on the potential tensions between these two alternative world views. The wireless future will include a mix of heterogenous wireless access technologies. Moreover, we expect that the two world views will converge such that vertically-integrated service providers will integrate WiFi or other WLAN technologies into their 3G or wire line infrastructure when this make sense. The multiplicity of potential wireless access technologies and /or business models provided some hope that we may be able to realize robust facilities - based competition for broadband local access services. If this occurs, it would help solve the "last mile" competition problem that has been deviled telecommunication policy.

SOME BACKGROUND ON WiFi AND 3G

3G:
3G is a technology for mobile service providers. Mobile services are provided by service providers that own and operate their own wireless networks and sell mobile services to and -users. Mobile service providers use licensed spectrum to provide wireless telephone coverage over some relatively large contiguous geographic service area. Today it may include the entire country. From a user's perspective, the key feature of mobile service is that it offers ubiquitous and continuous coverage. To support the service, mobile operators maintain a network of interconnected and overlapping mobile base stations that hand-off customers as those customers move among adjacent cells. Each mobile base station may support user's upto several kilometers away. The cell towers are connected to each other by a backhaul network that also provides interconnection to the wire line Public Switched Telecommunications Network (PSTN) and other services. The mobile system operator owns the end-to-end network from the base stations to the backhaul networks to the point of interconnection to the PSTN. Third
Generations (3G) mobile technologies will support higher bandwidth digital communications. To expand the range and capability of data services that can be supported by digital mobile systems, service providers will have to upgrade their networks to one of the 3G technologies which can support data rates of from 384Kbps up to 2Mbps.

WiFi
WiFi is the popular name for the wireless Ethernet 802.11b standard for WLANs . WiFi allows collections of PCs, terminals ,and other distributed computing devices to share resources and peripherals such as printers, access servers etc. One of the most popular LAN technologies was Ethernet.

HOW ARE WiFi AND 3G SAME
From the preceding discussion, it might appear that 3G and WiFi address completely different user needs in quiet distinct markets that do not overlap. While this was certainly more true about earlier generations of mobile services when compared with wired LANs or earlier versions of WLANs , it is increasingly not the case. The end- user does not care what technology is used to support his service. What matter is that both of these technologies are providing platforms for wireless access to the internet and other communication services.

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WIRELESS INTERNET ACCESS: 3G VS .Wifi?
ABSTRACT:
This paper compares and contrasts two technologies for delivering broadband wireless Internet access services:"3G" VS."WiFi". The former, 3G, refers to the collection of third generation mobile technologies that are designed to allow mobile operators to offer integrated data and voice services over mobile networks .The latter, WiFi, refers to the 802.11b wireless Ethernet standard that was designed to support wireless LANs. Although the two technologies reflect fundamentally different service, industry and architectural design goals, origins and philosophies, each has recently attracted a lot of attention as candidates for the dominant platform for providing broadband wireless access to the Internet. It remains an open question as to the extent to which these two technologies are in competition or, perhaps, may be complementary. If they are viewed as in competition, then the triumph of one at the expense of the other would be likely to have profound implications for the evolution of the wireless internet and structure of the service provider industry.
INTRODUCTION:
The two most important phenomena impacting telecommunications over the past decade have been explosive parallel growth of both the internet and mobile telephone services. The internet brought the benefits of data communications to the masses with email, the web, and ecommerce; while mobile service has enabled "follow-me anywhere/always on" telephony. The internet helped accelerate the trend from voice-centric to data-centric networking. Data already exceeds voice traffic and the data share continues to grow. Now these two worlds are converging. This convergence offers the benefits of new interactive multimedia services coupled to the flexibility and mobility of wireless. To realize the full potential of this convergence, however, we need broadband access connections.
Here we compare and contrast two technologies that are likely to play important roles: Third Generation mobile ("3G") and Wireless Local Area Networks ("WLAN") . The former represents a natural evolution and extension of the business models of existing mobile providers. In contrast, the WiFi approach would leverage the large installed base of WLAN infrastructure already in place. We use 3G and WiFi as
shorthand for the broad classes of related technologies that have two quiet distinct industry origins and histories.
Speaking broadly, 3G offers a vertically -integrated , top -down , service -provider approach to delivering wireless internet access , while WiFi offers an end -user -centric , decentralized approach to service provisioning. We use these two technologies to focus our speculations on the potential tensions between these two alternative world views. The wireless future will include a mix of heterogenous wireless access technologies. Moreover, we expect that the two world views will converge such that vertically-integrated service providers will integrate WiFi or other WLAN technologies into their 3G or wire line infrastructure when this make sense. The multiplicity of potential wireless access technologies and /or business models provided some hope that we may be able to realize robust facilities - based competition for broadband local access services. If this occurs, it would help solve the "last mile" competition problem that has been deviled telecommunication policy.
SOME BACKGROUND ON WiFi AND 3G
3G:
3G is a technology for mobile service providers. Mobile services are provided by service providers that own and operate their own wireless networks and sell mobile services to and -users. Mobile service providers use licensed spectrum to provide wireless telephone coverage over some relatively large contiguous geographic service area. Today it may include the entire country. From a user's perspective, the key feature of mobile service is that it offers ubiquitous and continuous coverage. To support the service, mobile operators maintain a network of interconnected and overlapping mobile base stations that hand-off customers as those customers move among adjacent cells. Each mobile base station may support user's upto several kilometers away. The cell towers are connected to each other by a backhaul network that also provides interconnection to the wire line Public Switched Telecommunications Network (PSTN) and other services. The mobile system operator owns the end-to-end network from the base stations to the backhaul networks to the point of interconnection to the PSTN. Third Generations (3G) mobile technologies will support higher bandwidth digital communications. To expand the range and capability of data services that can be supported by digital mobile systems, service providers will have to upgrade their networks to one of the 3G technologies which can support data rates of from 384Kbps up to 2Mbps.
WiFi
WiFi is the popular name for the wireless Ethernet 802.11b standard for WLANs . WiFi allows collections of PCs, terminals ,and other distributed computing devices to share resources and peripherals such as printers, access servers etc. One of the most popular LAN technologies was Ethernet.
WiFi LANs operate using unlicensed spectrum in the 2.4 GHz band . The current generation of WLANs supports upto 11Mbps, data rates within 300 feet of the
base station. Most typically , WLANs are deployed in a distributed way to offer last -few - hundred - feet connectivity to a wire line backbone corperate or campus network. Typically, the WLANs are implemented as part of a private network. The base station equipment is owned and operated by the end-user community .Although each base station can support connections only over a range of few hundred feet, it is possible to provide contiguous coverage over a wider area by using multiple base stations. Still, the WLAN technology was not designed to support high-speed hand - off associated with users moving between base station coverage areas.
There has been an emergence of a number of service providers that are offering WiFi services for a fee in selected local areas . In addition, there is a growing movement of so - called "Free Nets" where individuals or organizations are providing open access to subsidized WiFi networks
HOW ARE WiFi AND 3G SAME
From the preceding discussion, it might appear that 3G and WiFi address completely different user needs in quiet distinct markets that do not overlap. While this was certainly more true about earlier generations of mobile services when compared with wired LANs or earlier versions of WLANs , it is increasingly not the case. The end- user does not care what technology is used to support his service. What matter is that both of these technologies are providing platforms for wireless access to the internet and other communication services.
We shall focus on the ways in which the two technologies may be thought of as
similar.
A.BOTH ARE WIRELESS
Both technologies are wireless which
(1) Avoids need to install cable drops to each device when compared to wire line
alternatives.
(2) Facilities mobility,
Wireless infrastructure may be deployed more rapidly than wire line alternatives to respond to new market opportunities or changing demand. Wireless technologies also facilitate mobility. This includes both
(1) The ability to move devices around having to move cables and furniture and
(2) The ability to stay continuously connected over wider serving areas.
3G offers much narrower bandwidth but over a wider covering area and with more support for rapid movement between base stations. Although it is possible to cover a wide area with WiFi , it is most commonly deployed in a local area with one or a few base stations being managed as a separate WLAN .
This has implications for the magnitude of initial investment required to bring up WLAN or 3G wireless service .It is unclear at this time which type of network might be lower cost for equivalent scale deployments. B. BOTH ARE ACCESS TECHNOLOGIES.
Both 3G and WiFi are access or edge/network technologies. This means they offer alternatives to the last- mile wireline network. Beyond the last -mile , both rely on similar network connections and transmission support infrastructure. For 3G, the wireless link is from the end- user device to the cell base station ( up to a few kilometers) and then dedicated wireline facilities to interconnect base station to the carrier's backbone
For WiFi , the wireless link is a few hundred feet from the end-user device to the base station. The base station is then connected either into the wireline LAN or enterprise network infrastructure or to a wireline access line to a carrier's backbone network and then eventually to the internet . Wireless service are part of an end-to-end value chain that includes , in its coarsest delineation atleast
(1) The internet backbone ( the cloud )
(2) The second mile network providers (ILEC ,mobile , cable, or a NextGen carrier (1) The last mile access facilities ( and, beyond them, the end-user devices ).
C. BOTH OFFER BROADBAND DATA SERVICE
Both 3G and WiFi support broadband data service, although the data rate offered by WiFi ( 11Mbps ) is substantially higher than the couple of hundred Kbps expected from 3G services .
The key is that both will offer sufficient bandwidth to support a comparable array of services , including real - time voice, data , and streaming media . In this sense both will support "broadband " where we define this as "faster than what we had before".
Both services will also support "always on " connectivity which is another very important aspect of broadband service . This is even more important than the raw throughput supported .
HOW THEY ARE DIFFERENT
We shall consider several of the important ways in which the WiFi and 3G approaches to offering broadband wireless access services are substantively different. A . CURRENT BUSINESS MODELS / DEPLOYMENT ARE
DIFFERENT
3G represents an extension of the mobile service provider model. The basic business model is the telecommunication services model . The 3G business model is close to the wireline telephone business. The service is conceptualized usually as a mass - market offering to both residential and business customers on a subscription basis . The
3G deployment and serving provisioning model is one of top-down , vertically -integrated , and centralized planning and operation.
In contrast, WiFi comes out of the data communications industry ( LANs) which is a bi-product of the computer industry . The basic business model is one of equipment makers who sell boxes to customers. Only recently have WLANs being targeted as a mass market offering to home users.
With respect to deployment, 3G will require substantial investment in new infrastructure to upgrade existing 2G networks. For WiFi , it is hoped that deployment can piggy-back on the large existing base of WLAN equipment already in the field . In both the cases, end - user will need to buy suitable interface devices (PC cords for 3G or WiFi access) .
The prevailing business model for 3G services and infrastructure is vertically integrated, this need not be the case for WiFi . B. SPECTRUM POLICY AND MANAGEMENT.
This is one of the key distinctions between 3G and WiFi . 3G and other mobile technologies use licensed spectrum, while WiFi uses unlicensed shared spectrum. This has important implications for
(1) Cost of service
(2) Quality of service (QOS ) and congestion management
(3) Industry structure
With licensed spectrum, the licensee is protected from interference from other service providers . In contrast, the unlicensed spectrum used by WiFi imposes strict power limits on users and forces users to accept interference from others. Hence WiFi network cannot control potential interference from other WiFi service providers or the RF sources that are sharing the unlicensed spectrum.
C. STATUS OF TECHNOLOGY DEVELOPMENT DIFFERENT.
The two technologies differ with respect to their stage of development in a number of ways .
1. DEPLOYMENT STATUS.
While 3G licenses have been awarded in a number of markets at a cost of billions of dollars to the licensees, it has only limited progress with respect to service deployment. In contrast, we have a large installed base of WiFi networking equipment that is growing rapidly.
2. EMBEDDED SUPPORT FOR SERVICES.
Important difference between 3G and WiFi is their embedded support for voice services . 3G was expressly designed as an upgrade technology for wireless voise telephony networks. In contrast, WiFi provides a lower layer data communication service that can be used as the substrate on which to layer services such as voice telephony . Another potential advantage of 3G over WiFi is that 3G offers better support for secure / private communications that does WiFi.
3. STANDARDIZATION
Formal standards picture for 3G is perhaps more clear than for WLAN . For 3G , there's relatively a small family of internationally sanctioned standards, collectively referred to as WCDMA . WiFi is one of the families of continuously evolving 802.11 x wireless Ethernet standards. It may appear that the standards picture for WLANs is less clear than for 3G.
4. SERVICE/BUSINESS MODEL
3G is more developed than WiFi as a business and service model. It represents an extension of the existing service provider industry to new services, and as such, does not represent a radical departure from underlying industry structure. In contrast, WiFi is more developed with respect to the upstream supplier markets, at least with respect to WLAN equipment.
SOME IMPLICATIONS FOR INDUSTRY STRUCTURE AND PUBLIC POLICY
1. WiFi is good for competition
2. WiFi and 3G can compliment each other for a mobile provider.
3. Policy is key.
4. Spectrum Success of WiFi is potentially good for multimedia content.
5. Technical progress favors heterogeneous future.
CONCLUSION:
This article offers a qualitative comparision of two wireless technologies that can be viewed simultaneously as substitute and / or complimentary paths for evolving to broad band wireless access. The two technologies are 3G , which is the preferred upgrade path for mobile providers , and WiFi , one of the many WLAN technologies. The goal of the analysis is to explore two divergent world views for the future of wireless access and to speculate on the likely success and possible interactions between the two technologies in the future. First, both technologies are likely to succeed in the market place. This means that the wireless future will include heterogeneous access technologies. Second we expect 3G mobile providers to integrate WiFi technology into their networks thus expecting these two technologies to be complimentary in their successful mass market deployment .Third, we also expect WiFi to offer competition to 3G providers because of the lower enter costs associated with establishing WiFi networks. This may take form of new type of service providers (e.g.,Boingo) , in end- user organized networks (e.g., FreeNet aggregation). The threat of such WiFi competition is beneficial to prospects for the future of last mile competition.
REFERENCES:
1. Workshop "competition in wireless : spectrum , service and technology
wars , university of Florida, Feb 20,2002.
2. From the internet sites of MIT.

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Wireless Internet Access: 3G vs. WiFi
Abstract
This paper compares and contrasts two technologies for delivering broadband wirelessInternet access services: "3G" vs. "WiFi". The former, 3G, refers to the collection of thirdgeneration cellular technologies that are designed to allow mobile cellular operators tooffer integrated data and voice services over cellular networks. The latter, WiFi, refers tothe 802.11b wireless Ethernet standard that was designed to support wireless LANs.Although the two technologies reflect fundamentally different service, industry, andarchitectural design goals, origins, and philosophies, each has recently attracted a lot ofattention as candidates for the dominant platform for providing broadband wirelessaccess to the Internet. It remains an open question as to the extent to which these twotechnologies are in competition or, perhaps, may be complementary. If they are viewed asin competition, then the triumph of one at the expense of the other would be likely tohave profound implications for the evolution of the wireless Internet and service providerindustry structure. The goal of the qualitative discussion of these two technologies is toprovide a more concrete understanding of the differing worldviews encompassed by thesetechnologies and their relative strengths and weaknesses in light of the forces shaping theevolution of wireless Internet services.I. Introduction
The two most important phenomena impacting telecommunications over the pastdecade have been the explosive parallel growth of both the Internet and cellular telephoneservices. The Internet brought the benefits of data communications to the masses withemail, the Web, and eCommerce; while cellular service has enabled "follow-meanywhere/always on" telephony. The Internet helped accelerate the trend from voicecentricto data-centric networking. Data already exceeds voice traffic and the data sharecontinues to grow. Now, these two worlds are converging. This convergence offers the1 This most recent draft was prepared by William Lehr, without the benefit of a final review from LeeMcKnight.3G vs. WiFi Lehr & McKnightPage 2 of 18benefits of new interactive multimedia services coupled to the flexibility and mobility ofwireless. To realize the full potential of this convergence, however, we need broadbandaccess connections. What precisely constitutes "broadband" is, of course, a movingtarget, but at a minimum, it should support data rates in the hundreds of kilobits persecond as opposed to the 50Kbps enjoyed by 80% of the Internet users in the US whostill rely on dial-up modems over wireline circuits, or the even more anemic 10-20Kbpstypically supported by those cellular providers that even bother to offer data services.While the need for broadband wireless Internet access is widely accepted, there remainsgreat uncertainty and disagreement as to how the wireless Internet future will evolve.The goal of this paper is to compare and contrast two important technologies thatare likely to play important roles: Third Generation Cellular ("3G") and Wireless LocalArea Networks ("WLAN"). Specifically, we will focus on 3G as embodied by the UMTSand WCDMA standards versus the WLAN technology embodied by the WiFi or 802.11bstandard, which is the most popular and widely deployed of the WLAN technologies. Weuse these technologies as reference points to span what we believe are two fundamentallydifferent philosophies for how wireless Internet access might evolve. The formerrepresents a natural evolution and extension of the business models of existing cellularproviders. These providers have already invested billions of dollars purchasing thespectrum licenses to support advanced data services and equipment makers have beengearing up to produce the base stations and handsets for wide-scale deployments of 3Gservices. In contrast, the WiFi approach would leverage the huge installed base of WLANinfrastructure already in place in many government, university, and corporateenvironments and the supporting industry of equipment makers.In focusing on 3G and WiFi, we are ignoring many other technologies that arelikely to be important in the wireless Internet such as satellite services, LMDS, MMDS,or other fixed wireless alternatives. We also ignore technologies such as BlueTooth orHomeRF which have at times been touted as potential rivals to WiFi, at least in homenetworking environments. Moreover, we will not discuss the relationship betweenvarious transitional, or "2.5G" cellular technologies such as GPRS and 3G, nor will wediscuss the myriad possibilities for "4G" cellular technologies. While all of these areinteresting, we have only limited space and our goal is to tease out what we believe areimportant themes/trends/forces shaping the industry structure for next generation wirelessservices, rather than to focus on the technologies themselves. We use 3G and WiFi asshorthand for broad classes of related technologies that have two quite distinct industryorigins and histories.Speaking broadly, 3G offers a vertically-integrated, top-down, service-providerapproach to delivering wireless Internet access; while WiFi offers (at least potentially) anend-user-centric, decentralized approach to service provisioning. Although there isnothing intrinsic to the technologies that dictates that one may be associated with onetype of industry structure or another, we use these two technologies to focus ourspeculations on the potential tensions between these two alternative world views.We believe that the wireless future will include a mix of heterogeneous wirelessaccess technologies. Moreover, we expect that the two worldviews will converge such3G vs. WiFi Lehr & McKnightPage 3 of 18that vertically-integrated service providers will integrate WiFi or other WLANtechnologies into their 3G or wireline infrastructure when this makes sense. We are,perhaps, less optimistic about the prospects for decentralized, bottom-up networks –however, it is interesting to consider what some of the roadblocks are to the emergence ofsuch a world. The latter sort of industry structure is attractive because it is likely to bequite competitive, whereas the top-down vertically-integrated service-provider modelmay – but need not be -- less so. The multiplicity of potential wireless accesstechnologies and/or business models suggests that we may be able to realize robustfacilities-based competition for broadband local access services. If it occurs, this wouldhelp solve the "last mile" competition problem that has bedeviled telecommunicationspolicy.II. Some background on WiFi and 3G
In this section, we provide a brief overview of the two technologies to help orientthe reader. We will discuss each of the technologies in turn.A. 3G
3G is a technology for mobile cellular service providers. Mobile cellular servicesare provided by service providers that own and operate their own wireless networks andsell cellular services to end-users, usually on a monthly subscription basis. Mobile serviceproviders use licensed spectrum to provide wireless telephone coverage over somerelatively large contiguous geographic serving area. Historically, this might haveincluded a metropolitan area. Today it may include the entire country. From a usersperspective, the key feature of cellular service is that it offers (near) ubiquitous andcontinuous coverage. That is, a consumer can carry on a telephone conversation whiledriving along a highway at 100 Km/hour. To support this service, cellular operatorsmaintain a network of interconnected and overlapping cellular base stations that hand-offcustomers as those customers move among adjacent cells. Each cellular base station maysupport users up to several kilometers away. The cell towers are connected to each otherby a backhaul network that also provides interconnection to the wireline Public SwitchedTelecommunications Network (PSTN) and other services. The mobile system operatorowns the end-to-end network from the base stations to the backhaul network to the pointof interconnection to the PSTN (and, perhaps, parts thereof).The first mobile cellular services were analog. Although mobile services began toemerge in the 1940s, the first mass market mobile services in the U.S. were based on theAMPS (Advanced Mobile Phone Service) technology. This is what is commonly referredto as first generation wireless. The FCC licensed two operators in each market to offerAMPS service in the 800-900MHz band. In the 1990s, cellular services based on digitalmobile technologies ushered in the second generation (2G) of wireless services that wehave today. These were referred to as Personal Communication Systems (PCS) and usedtechnologies such as TDMA (Time Division Multiple Access), CDMA (Code DivisionMultiple Access) and GSM (Global System for Mobile Communications). From 1995 to1997, the FCC auctioned off PCS spectrum licenses in the 1850 to 1990 MHz band.CDMA and TDMA were deployed in the various parts of the U.S., while GSM was3G vs. WiFi Lehr & McKnightPage 4 of 18deployed as the common standard in Europe. The next or Third Generation (3G) cellulartechnologies will support higher bandwidth digital communications and are expected tobe based on the UMTS (Universal Mobile Telecommunications System) or WCDMA(Wideband CDMA) technologies.The chief focus of wireless mobile services has been voice telephony. However,in recent years there has been growing interest in data services as well. While dataservices are available over AMPS systems, these are limited to quite low data rates(<10Kbps). Higher speed data and other advanced telephone services are more readilysupported over the digital cellular 2G systems. The 2G systems also support largernumbers of subscribers and so helped alleviate capacity problems faced by older AMPSsystems in more congested environments. Nevertheless, the data rates supportable over2G systems are still quite limited, offering only between 10-20Kbps. To expand the rangeand capability of data services that can be supported by digital cellular systems, serviceproviders will have to upgrade their networks to one of the 3G technologies. These cansupport data rates of from 384Kbps up to 2Mbps, although most commercialdeployments are expected to offer data rates closer to 100Kbps in practice. While this issubstantially below the rates supported by the current generation of wireline broadbandaccess services such as DSL or cable modems, it is expected that future upgrades to the3G or the transition to 4G cellular services will offer substantially higher bandwidths.Although wireline systems are likely to always exceed the capacity of wireless ones, itremains unclear precisely how much bandwidth will be demanded by the typicalconsumer and whether 3G services will offer enough to meet the needs of mostconsumers.Auctions for 3G spectrum licenses occurred in a number of countries in 2000 andthe first commercial offerings of 3G services began in Japan in October 2001. Morerecently, Verizon Wireless has announced "3G" service in portions of its serving territory(although this is not true-3G service).B. WiFi
WiFi is the popular name for the wireless Ethernet 802.11b standard for WLANs.Wireline local area networks (LANs) emerged in the early 1980s as a way to allowcollections of PCs, terminals, and other distributed computing devices to share resourcesand peripherals such as printers, access servers, or shared storage devices. One of themost popular LAN technologies was Ethernet. Over the years, the IEEE has approved asuccession of Ethernet standards to support higher capacity LANs over a diverse array ofmedia. The 802.11x family of Ethernet standards are for wireless LANs.WiFi LANs operate using unlicensed spectrum in the 2.5GHz band. The currentgeneration of WLANs support 10Mbps data rates within 300 feet of the base station.Most typically, WLANs are deployed in a distributed way to offer last-few-hundred-feetconnectivity to a wireline backbone corporate or campus network. Typically, the WLANsare implemented as part of a private network. The base station equipment is owned andoperated by the end-user community as part of the corporate enterprise network, campus3G vs. WiFi Lehr & McKnightPage 5 of 18or government network. In most cases, use of the network is free to end-users (subsidizedby the community as a cost of doing business, like corporate phones).Although each base station can support connections only over a range of a fewhundred feet, it is possible to provide contiguous coverage over a wider area by usingmultiple base stations. A number of corporate business and university campuses havedeployed such contiguous WLANs. Still, the WLAN technology was not designed tosupport high-speed hand-off associated with users moving between base station coverageareas (i.e., the problem addressed by mobile cellular systems).In the last two years, we have seen the emergence of a number of serviceproviders that are offering WiFi services for a fee in selected local areas such as hotels,airport lounges, and coffee shops. Mobilstar, which declared bankruptcy during the latterhalf of 2001, was one of the leaders in this area. In addition, there is a growing movementof so-called "FreeNets" where individuals or organizations are providing open access tosubsidized WiFi networks.In contrast to mobile cellular, WLANs were principally focused on supportingdata communications. However, with the growing interest in supporting real-timeservices such as voice and video over IP networks, it is both possible and increasingly thecase that voice telephony services are being offered over WLANs.III. How are WiFi and 3G same
From the preceding discussion, it might appear that 3G and WiFi addresscompletely different user needs in quite distinct markets that do not overlap. While thiswas certainly more true about earlier generations of cellular services when compared withwired LANs or earlier versions of WLANs, it is increasingly not the case. The end-userdoes not care what technology is used to support his service. What matters is that both ofthese technologies are providing platforms for wireless access to the Internet and othercommunication services.In this section we focus on the ways in which the two technologies may bethought of as similar, while in the next section we will focus on the many differencesbetween the two.A. Both are wireless
Both technologies are wireless which (1) avoids need to install cable drops toeach device when compared to wireline alternatives; and (2) facilitates mobility.Avoiding the need to install or reconfigure local distribution cable plant can represent asignificant cost savings, whether it is within a building, home, or in the last miledistribution plant of a wireline service provider. Moreover, many types of wirelessinfrastructure can provide scalable infrastructure when penetration will increase onlyslowly over time (e.g., when a new service is offered or in an overbuild scenario). Newbase stations are added as more users in the local area join the wireless network and cellsare resized. Wireless infrastructure may be deployed more rapidly than wireline3G vs. WiFi Lehr & McKnightPage 6 of 18alternatives to respond to new market opportunities or changing demand. These aspectsof wireless may make it attractive as an overbuild competitor to wireline local access,which has large sunk/fixed costs that are more susceptible to the homes passed than theactual level of subscribership. The high upfront cost of installing new wireline last-milefacilities is one of the reasons why these may be a natural monopoly.Wireless technologies also facilitate mobility. This includes both the ability tomove devices around without having to move cables and furniture and the ability to staycontinuously connected over wider serving areas. We refer to the first as local mobilityand this is one of the key advantages of WLANs over traditional wireline LANs. Thesecond type of mobility is one of the key advantages of cellular systems such as 3G.WLANs trade the range of coverage for higher bandwidth, making them more suitablefor "local hot spot" service. In contrast, 3G offers much narrower bandwidth but over awider calling area and with more support for rapid movement between base stations.Although it is possible to cover a wide area with WiFi, it is most commonly deployed in alocal area with one or a few base stations being managed as a separate WLAN. Incontrast, a 3G network would include a large number of base stations operating over awide area as an integrated wireless network to enable load sharing and uninterruptedhand-offs when subscribers move between base stations at high speeds.This has implications for the magnitude of initial investment required to bring upWLAN or 3G wireless service and for the network management and operations supportservices required to operate the networks. However, it is unclear at this time which typeof network might be lower cost for equivalent scale deployments, either in terms ofupfront capital costs (ignoring spectrum costs for now) or on-going network managementcosts.B. Both are access technologies
Both 3G and WiFi are access or edge-network technologies. This means theyoffer alternatives to the last-mile wireline network. Beyond the last-mile, both rely onsimilar network connections and transmission support infrastructure. For 3G, the wirelesslink is from the end-user device to the cell base station which may be at a distance of upto a few kilometers, and then dedicated wireline facilities to interconnect base stations tothe carrier's backbone network and ultimately to the Internet cloud. The local backhaulinfrastructure of the cell provider may be offered over facilities owned by the wirelessprovider (e.g., microwave links) or leased from the local wireline telephone serviceprovider (i.e., usually the incumbent local exchange carrier or ILEC). Although 3G isconceived of as an end-to-end service, it is possible to view it as an access service.For WiFi, the wireless link is a few hundred feet from the end-user device to thebase station. The base station is then connected either into the wireline LAN or enterprisenetwork infrastructure or to a wireline access line to a carrier's backbone network andthen eventually to the Internet. For example, WiFi is increasingly finding application as ahome LAN technology to enabling sharing of DSL or cable modem residential broadbandaccess services among multiple PCs in a home or to enable within-home mobility. WiFiis generally viewed as an access technology, not an end-to-end service.

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WIRELESS INTERNET ACCESS: 3G VS .Wifi?
ABSTRACT:
This paper compares and contrasts two technologies for delivering broadband wireless Internet access services:"3G" VS."WiFi". The former, 3G, refers to the collection of third generation mobile technologies that are designed to allow mobile operators to offer integrated data and voice services over mobile networks .The latter, WiFi, refers to the 802.11b wireless Ethernet standard that was designed to support wireless LANs. Although the two technologies reflect fundamentally different service, industry and architectural design goals, origins and philosophies, each has recently attracted a lot of attention as candidates for the dominant platform for providing broadband wireless access to the Internet. It remains an open question as to the extent to which these two technologies are in competition or, perhaps, may be complementary. If they are viewed as in competition, then the triumph of one at the expense of the other would be likely to have profound implications for the evolution of the wireless internet and structure of the service provider industry.INTRODUCTION:
The two most important phenomena impacting telecommunications over the past decade have been explosive parallel growth of both the internet and mobile telephone services. The internet brought the benefits of data communications to the masses with email, the web, and ecommerce; while mobile service has enabled "follow-me anywhere/always on" telephony. The internet helped accelerate the trend from voice-centric to data-centric networking. Data already exceeds voice traffic and the data share continues to grow. Now these two worlds are converging. This convergence offers the benefits of new interactive multimedia services coupled to the flexibility and mobility of wireless. To realize the full potential of this convergence, however, we need broadband access connections.
Here we compare and contrast two technologies that are likely to play important roles: Third Generation mobile ("3G") and Wireless Local Area Networks ("WLAN") . The former represents a natural evolution and extension of the business models of existing mobile providers. In contrast, the WiFi approach would leverage the large installed base of WLAN infrastructure already in place. We use 3G and WiFi as
shorthand for the broad classes of related technologies that have two quiet distinct industry origins and histories.
Speaking broadly, 3G offers a vertically -integrated , top -down , service -provider approach to delivering wireless internet access , while WiFi offers an end -user -centric , decentralized approach to service provisioning. We use these two technologies to focus our speculations on the potential tensions between these two alternative world views. The wireless future will include a mix of heterogenous wireless access technologies. Moreover, we expect that the two world views will converge such that vertically-integrated service providers will integrate WiFi or other WLAN technologies into their 3G or wire line infrastructure when this make sense. The multiplicity of potential wireless access technologies and /or business models provided some hope that we may be able to realize robust facilities - based competition for broadband local access services. If this occurs, it would help solve the "last mile" competition problem that has been deviled telecommunication policy.SOME BACKGROUND ON WiFi AND 3G
3G:
3G is a technology for mobile service providers. Mobile services are provided by service providers that own and operate their own wireless networks and sell mobile services to and -users. Mobile service providers use licensed spectrum to provide wireless telephone coverage over some relatively large contiguous geographic service area. Today it may include the entire country. From a user's perspective, the key feature of mobile service is that it offers ubiquitous and continuous coverage. To support the service, mobile operators maintain a network of interconnected and overlapping mobile base stations that hand-off customers as those customers move among adjacent cells. Each mobile base station may support user's upto several kilometers away. The cell towers are connected to each other by a backhaul network that also provides interconnection to the wire line Public Switched Telecommunications Network (PSTN) and other services. The mobile system operator owns the end-to-end network from the base stations to the backhaul networks to the point of interconnection to the PSTN. Third Generations (3G) mobile technologies will support higher bandwidth digital communications. To expand the range and capability of data services that can be supported by digital mobile systems, service providers will have to upgrade their networks to one of the 3G technologies which can support data rates of from 384Kbps up to 2Mbps.WiFi
WiFi is the popular name for the wireless Ethernet 802.11b standard for WLANs . WiFi allows collections of PCs, terminals ,and other distributed computing devices to share resources and peripherals such as printers, access servers etc. One of the most popular LAN technologies was Ethernet.
WiFi LANs operate using unlicensed spectrum in the 2.4 GHz band . The current generation of WLANs supports upto 11Mbps, data rates within 300 feet of the
base station. Most typically , WLANs are deployed in a distributed way to offer last -few - hundred - feet connectivity to a wire line backbone corperate or campus network. Typically, the WLANs are implemented as part of a private network. The base station equipment is owned and operated by the end-user community .Although each base station can support connections only over a range of few hundred feet, it is possible to provide contiguous coverage over a wider area by using multiple base stations. Still, the WLAN technology was not designed to support high-speed hand - off associated with users moving between base station coverage areas.
There has been an emergence of a number of service providers that are offering WiFi services for a fee in selected local areas . In addition, there is a growing movement of so - called "Free Nets" where individuals or organizations are providing open access to subsidized WiFi networksHOW ARE WiFi AND 3G SAME
From the preceding discussion, it might appear that 3G and WiFi address completely different user needs in quiet distinct markets that do not overlap. While this was certainly more true about earlier generations of mobile services when compared with wired LANs or earlier versions of WLANs , it is increasingly not the case. The end- user does not care what technology is used to support his service. What matter is that both of these technologies are providing platforms for wireless access to the internet and other communication services.
We shall focus on the ways in which the two technologies may be thought of as
similar.A.BOTH ARE WIRELESS
Both technologies are wireless which
(1) Avoids need to install cable drops to each device when compared to wire line
alternatives.
(2) Facilities mobility,
Wireless infrastructure may be deployed more rapidly than wire line alternatives to respond to new market opportunities or changing demand. Wireless technologies also facilitate mobility. This includes both
(1) The ability to move devices around having to move cables and furniture and
(2) The ability to stay continuously connected over wider serving areas.
3G offers much narrower bandwidth but over a wider covering area and with more support for rapid movement between base stations. Although it is possible to cover a wide area with WiFi , it is most commonly deployed in a local area with one or a few base stations being managed as a separate WLAN .
This has implications for the magnitude of initial investment required to bring up WLAN or 3G wireless service .It is unclear at this time which type of network might be lower cost for equivalent scale deployments. B. BOTH ARE ACCESS TECHNOLOGIES.
Both 3G and WiFi are access or edge/network technologies. This means they offer alternatives to the last- mile wireline network. Beyond the last -mile , both rely on similar network connections and transmission support infrastructure. For 3G, the wireless link is from the end- user device to the cell base station ( up to a few kilometers) and then dedicated wireline facilities to interconnect base station to the carrier's backbone
For WiFi , the wireless link is a few hundred feet from the end-user device to the base station. The base station is then connected either into the wireline LAN or enterprise network infrastructure or to a wireline access line to a carrier's backbone network and then eventually to the internet . Wireless service are part of an end-to-end value chain that includes , in its coarsest delineation atleast
(1) The internet backbone ( the cloud )
(2) The second mile network providers (ILEC ,mobile , cable, or a NextGen carrier (1) The last mile access facilities ( and, beyond them, the end-user devices ).

3G vs Wi-Fi.ppt (Size: 4.03 MB / Downloads: 60)
Introduction & Technology
Cellular Technology & Evolution 3G & Wi-Fi
3G,refers to collection of 3rd generation mobile technologies
Wi-Fi, refers to 802.11b wireless Ethernet standards to support wireless LANs3G
Technology for mobile service providers
Use licensed spectrum to provide wireless telephone coverage
Base station support up to several kilometers
Support higher bandwidth digital communications
Data rates from 384Kbs up to 2MbpsWi-Fi
Wi-Fi is popular name for wireless Ethernet 802.11b
Operate using unlicensed spectrum in the 2.4Ghz band
Base station support within few feet
Data rate up to 11 Mbps
Wi-Fi comes out from data communication industry(LANs) which is bi-product of the computer industry
WLAN Technologies/Protocols
IEEE 802.11 ( b, g & a) --Wi-Fi
IEEE 802.16 (a) -- Wi -Max or Wider – Fi
Wi-MAX (Worldwide Interoperability for Microwave Access) provides fixed & mobile internet access
IEEE 802.20 -- Mobile – Fi
Mobile Broadband Wireless Access (MBWA) or IEEE 802.20 is mobile broadband wireless networks, nicknamed as Mobile-Fi, it is low cost
IEEE 802.11 Specs. (Wi-Fi)
Comparisons
Comparisons: 3G vs. Wi-Fi
Comparisons: 3G vs. Wi-Max
Comparisons: 3G vs. Mobile-Fi
How is 3G & Wi-Fi same
Both are wireless
Both are access technologies
Both offer Broadband data service
Both are wireless
Avoids need to install cables
Facilities mobility
The ability to move devices
The ability to stay continuously connected to wider serving area
3G offers much narrower bandwidth but wider covering area & more support for rapid movement b/w base stations
Wi-Fi covers wide area but in local area with one or few base stations which is managed as a separate WLAN
Both are access technology
Both 3G & Wi-Fi are access or edge/network technologies
For 3G, the wireless link is up to a few kilometers & then dedicated wire line facilities to interconnected base station & ultimately to the internet cloud
For Wi-Fi, the wireless link is a few hundred feet from the user device to the base station, the base station is connected into the wire line LAN
Both offer broadband data storage
3G & Wi-Fi support broadband data service
The data rate offered by Wi-Fi(11Mbps) is higher than the couple of hundred Kbps expected from 3G
Both offer sufficient bandwidth to support services like real time voice, data and streaming media
How they are different
Spectrum policy and management
Status of technology development different
Development status
Embedded support
Standardization
business model
Spectrum policy & management
This is key distinction between 3G & Wi-Fi
This has important implications for
Cost of service
Quality of service(QOS)congestion management
Industry structure
The licensed spectrum used by 3G is protected from interference from other service
Wi-Fi is unlicensed & hence imposes strict power limits on other users and also interference from other service.
Status of tech development DEVELOPMENT STATUS
EMBEDDED SUPPORT FOR SERVICES
STANDARDIZATION
SERVICE/BUSSINESS MODEL
DEVELOPMENT STATUS
3G is used in market at a higher cost because of license, hence it has limited progress
In contrast, Wi-Fi networking is rapidly growingEMBEDDED SUPPORT SERVICE
3G was designed as upgraded technology for wireless voice service
Wi-Fi provides lower service for voice telephony and provides upgraded technology for data communication
Hence the potential advantage of 3G over Wi-Fi is that 3G offers better support for secure/private communication than Wi-Fi STANDARDIZTION
For 3G there is relatively a small family of internationally sanctioned standards, i.e., referred as WCDMA(Wideband Code Division Multiple Access)
Wi-Fi is one of the families of continuously evolving 802.11* wireless Ethernet standards.
The standards picture for WLANs is not clear as 3GSERVICE/BUSSINESS MODEL
3G is more developed than Wi-Fi as a business and service model
3G represents the extension of the existing service provider industry to new services
In contrast, Wi-Fi is more developed with respect to the supplier market, at least w.r.t. WLAN equipment
FutureIN FUTURE
Both Technologies are likely to succeed in the market
We expect 3G mobile providers to integrate Wi-Fi tech into their network
We expect Wi-Fi to offer competition to 3G providers because of the lower cost

The 3G network is the third generation of mobile networking and telecommunications. It features a wider range of services and advances network capacity over the previous 2G network. The 3G network also increases the rate of information transfer known as spectral efficiency.

Wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections. The Wi-Fi Alliance, the organization that owns the Wi-Fi (registered trademark) term specifically defines Wi-Fi as any "wireless local area network”

What is 3G?

Based on the International Telecommunications Union standards, the 3G network is the third generation of mobile networking and telecommunications.

A 3G network provides for download speeds of 14.4 megabits per second and uploads speeds of 5.8 megabits per second. The minimum speed for a stationary user is 2 megabits per second.

Japan and South Korea were the first countries to successfully launch this network. The Japanese company FOMA launched in May 2001 and South Korea's SK Telecom launched in January 2002.

Delays on the roll-out process of the 3G network impacted the growth of mobile technology in many countries. This network uses a different radio frequency than 2G, which forced many companies to build entirely new infrastructure and obtain additional licenses.

How Wi-Fi Technology works.

The wireless adapter of a computer translates data into radio signals and transmits the signals over an antenna. The transmitting antenna is generally connected to a DSL (Digital Subscriber Line) or a LAN-based Internet connection.

The Wi-Fi signals have a range of about 120 feet indoors and 300 feet outdoors. With an increase in the distance between the user and the signal, the connection speed decreases. Wi-Fi connections allow you to get rid of the clutter of wires.

The use of Wi-Fi technology for Internet access is on the rise. Companies and households have begun opting for wireless Internet access.